Portable electronic devices include rechargeable storage units, such as batteries, to provide power to internal system components. Through use of the portable electronic device, the battery is discharged. As a result, the battery may require charging from a power source to extend the operation of the portable electronic device. Many portable electronic devices may receive input power from the power source through a variety of different methods. For example, the portable electronic device may be coupled to an DC power source through an AC/DC adaptor. The portable electronic device may also be coupled to power sources through other methods, such as a universal serial bus (USB) connection.
The voltage range from various power sources may vary. For example, a USB input voltage range may range from 4.35 V to 5.5 V. An AC/DC adaptor may have various input voltages (e.g., 10 V, 15 V, 20 V) depending on the configurations of the specific AC/DC adaptor. In addition, the batteries used to power the portable electronic devices may have a variety of different voltage requirements for charging the batteries. As a result, charging the batteries and powering the internal system components during charging may require a relatively complex network of power converters to achieve the desired voltages.